1. Field of the Invention
This invention relates to sewing machines in general and more particularly to sewing machines having work feeding mechanisms of the drop feed variety in which the work engaging feed dog engages the work piece during the feed advance cycle and drops out of engagement with the work piece during the return cycle.
2. Description of the Prior Art
In a work feeding mechanism of the drop feed variety it is important that the feed bar supporting the feed dog be maintained parallel to the throat plate to insure that work fed by the feed dog will not drift toward the right or left side of the line of feed. It is also important for accurate stitch formation that the feed dog be centered within the feed dog accommodating slots in the throat plate and that it be adjusted to a correct elevation above the throat plate. One prior known work feeding mechanism employed a feed bar which supported a feed dog at one end and whose second end was suspended from the sewing machine bed by an adjustable pivot. The adjustable pivot permitted the feed dog to be laterally adjusted in the feed dog accommodating slots of the throat plate. See for example U.S. Pat. No. 3,527,183 to Szostak et al. A problem associated with prior art work feeding mechanisms such as that disclosed in U.S. Pat. No. 3,527,183 is the inability to independently adjust the centering, leveling and elevation of the feed dog while the work feeding mechanism is installed in a sewing machine.